Brittle stars (Echinodermata: Ophiuroidea) of coastal lagoons from the northern Yucatan Peninsula, Mexico

We present the first records of ophiuroids found in 6 tropical coastal lagoons of the northern Yucatan Peninsula. Specimens were collected from Ria Celestun, Chelem, Dzilam, Ria Lagartos, Yalahau, and Nichupte-Bojorquez lagoons, during May and June 2010. Six species belonging to the families Amphiuridae, Ophionereididae, and Ophiodermatidae were recorded. Amphiodia pulchella was recorded in all lagoons; Ophiostigma isocanthum was recorded only in Yalahau, and Ophionereis olivacea and Ophioderma appressa were recorded only in Nichupte-Bojorquez. Amphiodia cf. planispina was recorded in all the coastal lagoons except in Yalahau; all the individuals of this species were juveniles. Finally, Ophiophragmus filograneus was recorded in Ria Celestun, Ria Lagartos, and Nichupte-Bojorquez, being a new record for the southern Gulf of Mexico. The range of distribution of these species is extended and their presence in brackish waters is recorded, an environment that has not been properly studied concerning ophiuroids.